1. Field of the Invention
This invention relates to a living body data detector including a detector circuit that detects living body signals by processing signals generating across a pair of electrodes attached to a fitting belt, and a transmitter circuit for transmitting the living body signal data. The living body data detector constitutes a living body data measuring device together with a living body data display which displays the living body data upon receiving the living body signal data.
2. Description of the Related Art
A heart beat measuring instrument is a representative example of the living body data measuring device, and is, usually, constituted by a heart beat detector having a detector circuit for detecting heart beat signals by processing a cardiac potential generating across a pair of chest electrodes attached to a chest belt and a radio transmitter circuit for transmitting the heart beat signals, and a wristwatch type electronic timepiece including a radio receiver unit for receiving the heart beat signals, a heart beat operation circuit for calculating the heart rate by processing the heart beat signals, and a display circuit for displaying the heart rate.
Heart beat measuring instruments equipped with a chest belt have been disclosed in JP-A-6-245913, JP-A-2002-143110, JP-A-10-155753 and U.S. Pat. No. 5,491,474.
In these conventional heart beat measuring instruments, the chest belt itself has a width wider than that of a trouser belt but basically has the same structure. However, despite its decreased size and reduced weight, the heart beat measuring instrument mounted on the chest belt has a weight comparable to about that of a general wristwatch body. This is because the heart beat measuring instrument is constituted by having various electronic parts, a mechanical part, a cell and a casing for holding them. Therefore, when the conventional heart beat measuring instrument equipped with the chest belt is fitted to the human body, the position tended to be deviated due to the weight of the heart beat measuring instrument.
If it is attempted to prevent the deviation in position, the length-adjusting means must be operated to strongly fasten the chest belt so as to be fitted to the human body. However, the chest belt that is fitted by being strongly tightened presses the chest of the user causing such a problem that upon wearing the belt the user finds it uncomfortable being pressed and uneasy to breath. Another problem is that the electrode portions for detecting the cardiac potential must be brought into direct contact with the human body, and the living body data detector such as the heart beat measuring instrument that uses the chest belt must be fitted prior to wearing the clothing.